JANCD-TU01 is a dedicated operation panel terminal control unit manufactured by Yaskawa Electric, specially matched with Yaskawa series CNC system controllers. This unit acts as the signal transfer bridge between the machine tool operation panel and the main CNC control cabinet. It processes button input signals, indicator lamp output signals, mode selection signals and manual pulse generator transmission signals from the local operation panel, and transmits processed digital signals to the CNC main board through internal bus communication. Designed for industrial machine tool operating environments, it adopts industrial grade anti-interference circuit layout, compact onboard structure, and pluggable terminal wiring design to simplify on-site wiring and later maintenance, mainly used to expand and standardize the human-machine operation interface of Yaskawa CNC equipment.

The full model JANCD-TU01 can be split into several segments for interpretation one by one.

The operating power supply of the unit adopts DC 24V industrial standard power input, with rated working current of 0.3A and allowable input voltage fluctuation range from DC 20V to DC 28V. The working ambient temperature range is 0°C to 55°C, and the storage temperature range for long-term shutdown transportation is -20°C to 70°C. The relative humidity requirement for operation environment is 10% to 90% without condensation, and it can withstand vibration intensity of 10 to 150Hz frequency band with acceleration less than 0.5G. The overall hardware adopts surface mount industrial circuit board, with insulation resistance greater than 10MΩ between signal circuit and power circuit. The input signal supports NPN sinking type switch signal input, single channel input withstand voltage DC 30V maximum, output signal is transistor driving type, single channel maximum load current 20mA, can directly drive small signal indicator lights on the operation panel. The internal communication bus transmission rate is fixed matching Yaskawa CNC proprietary internal bus, signal scanning cycle is less than 1ms, ensuring real-time response of operation panel buttons. The overall installation size is standard cabinet card specification, suitable for plug-in installation inside the CNC electrical cabinet, with integrated EMC filtering circuit on the board to resist electromagnetic interference from servo drivers, contactors and frequency converters in the cabinet.

All external wiring interfaces of JANCD-TU01 adopt spring pluggable terminal row structure, divided into power supply terminal group, input signal terminal group, output signal terminal group and bus communication terminal group. The power supply terminal area reserves two terminals for DC24V positive pole and 0V ground connection, with independent fuse protection circuit inside the power loop. The input signal terminals are responsible for accessing all physical button signals on the machine operation panel, including mode switch buttons, axis jog buttons, start and stop buttons, reset buttons and feed override selection switches. The output signal terminals connect various status indicator lights on the operation panel, such as servo ready lamp, alarm lamp, program running lamp and spindle operating state lamp. A dedicated bus cable interface is reserved on the board for connecting the CNC main control motherboard, adopting Yaskawa private differential signal bus, without supporting third-party general field buses such as Modbus and Profibus. There is no external Ethernet or serial communication port on the unit, all data interaction is limited to internal communication inside the numerical control cabinet, and no external communication expansion channel is provided. A single reserved test signal pin is set on the edge of the circuit board for maintenance personnel to measure signal voltage and judge circuit faults.

First, real-time collection of operation panel switch input signals: continuously scan all button and switch signals transmitted from the operation panel, perform filtering and debounce processing on jitter signals generated by mechanical buttons to avoid misoperation caused by mechanical contact bounce, and upload valid operation commands to the CNC host in real time. Second, driving control of panel status indicator lights: receive state feedback signals sent by the CNC main system, convert digital logic signals into transistor driving output signals, control the on and off of each indicator light on the operation panel to feed back the current running state of the equipment to the operator. Third, signal isolation and transfer: build optocoupler isolation circuits between external panel signal loops and internal CNC bus circuits, isolate interference signals introduced by long-distance wiring of the operation panel to prevent external circuit short circuit or high voltage surge from damaging the core main board of the numerical control system. Fourth, hardware fault self-diagnosis: the unit has built-in basic detection logic for power supply circuit and input/output loop, when abnormal conditions such as power undervoltage, external signal short circuit and terminal open circuit occur, it will send fault code information to the CNC system, and the system displays the corresponding alarm content on the man-machine screen to prompt maintenance personnel. Fifth, standardized signal distribution conversion: unify the scattered discrete signals of different types of machine tool operation panels into standard bus signals identified by Yaskawa CNC host, reducing the difference of underlying signal logic between different machine tool structures.

This terminal unit is exclusively matched with medium and small Yaskawa CNC numerical control systems, mainly applied to vertical machining centers, horizontal milling machines, CNC lathes, drilling and tapping machines equipped with Yaskawa numerical control systems. It is suitable for independent operation panel layout machine tools where the operation panel is separated from the main electrical cabinet and connected by long wiring harnesses, solving the problem of signal attenuation and interference of long-distance panel wiring. It can be used in standard metal cutting processing workshops, hardware precision processing factories, mold manufacturing workshops and other general industrial production environments. It supports mass standardized assembly of machine tool manufacturers, unified the peripheral signal processing scheme of the operation panel for the same series of machine tools, reducing customized wiring and development work for equipment manufacturers. It is not applicable to ultra-high dust, strong corrosive gas, flammable and explosive special harsh environments, nor can it be used with non-Yaskawa brand third-party CNC main control systems, and cannot be matched with large-scale heavy-duty machine tools with ultra-multi-channel custom operation panels that require extended IO modules.

Before installation, confirm that the DC24V power supply output of the electrical cabinet is stable, cut off the total power supply of the CNC cabinet before plugging the unit into the card slot, and insert the board in place according to the card slot positioning guide rail to avoid poor contact of the gold finger caused by skew insertion. When wiring the external terminal row, the wire stripping length should be controlled within the standard range, and the terminal spring locking device must be completely clamped to prevent loose wiring during equipment vibration. The wiring harness of the operation panel should be separated from the high-power cable of the servo driver by more than 10 centimeters, and the signal wire should adopt shielded wire with single-point grounding of the shielding layer to reduce electromagnetic interference. Do not connect external voltage exceeding DC28V to the input and output terminals arbitrarily, and do not short-circuit the output terminal to DC24V positive pole, otherwise the on-board transistor driving circuit will be burned. During normal operation, keep the ventilation channel of the electrical cabinet unobstructed to avoid the ambient temperature around the unit exceeding 55°C for a long time, and do not place liquid, metal debris and dust on the surface of the circuit board.

Daily maintenance only needs to observe whether the system has alarm information related to the terminal unit, check whether the panel buttons and indicator lights respond normally during startup, and shut down the equipment in time if there is signal loss or abnormal light flashing. Conduct a comprehensive inspection every three months: cut off the total power supply, pull out the JANCD-TU01 board, use dry compressed air with low air pressure to blow off dust accumulated on the circuit board surface, check whether the terminal wiring is loose, whether the gold finger of the plug-in card has oxidation and blackening, and wipe the oxidized gold finger with soft insulating eraser. Every six months, test the input and output signal loops one by one with a multimeter, measure whether the input signal voltage is normal when pressing each button, and detect whether each output terminal has normal driving voltage when the indicator light is on. Avoid using water, alcohol or corrosive cleaning agents to directly wipe the circuit board during maintenance, and do not touch the chip pins on the board with bare hands to prevent static electricity from breaking down electronic components.

When the system reports a terminal unit communication failure, first check whether the bus connecting cable between the unit and the main board is loose or damaged, and re-plug or replace the bus cable for testing. If a single button or indicator light fails to work, check the corresponding terminal wiring first, and judge whether the internal circuit of the unit is damaged after eliminating external wiring faults. If the power supply circuit of the board is burned or multiple channels of input and output are completely invalid, the whole board needs to be replaced with the same model JANCD-TU01, and the power supply must be cut off during replacement operation. Discarded faulty boards cannot be discarded randomly, and need to be recycled as industrial electronic waste in accordance with local industrial equipment waste disposal standards. Do not disassemble the circuit board privately for maintenance without professional electronic maintenance equipment, disassembly will destroy the on-board sealing and anti-interference structure and void the product warranty.